1. Technical Field
The present invention relates to a cutter moving mechanism configured to move a cutter blade linearly and cut sheet media, and to a cutter. The invention also relates to a printer having the cutter.
2. Related Art
A printer with a cutter is described in JP-A-2005-161481. The cutter in JP-A-2005-161481 has cutter blade moving mechanism that drives a cutter blade reciprocally between a forward position where the recording paper is cut and a retracted position separated from the forward position. The cutter blade moving mechanism has a drive motor, two cutter drive gears to which drive power is transferred from the drive motor, and a guide that guides the movable knife in the forward/back direction. The two cutter drive gears are arranged in a perpendicular direction perpendicular to the forward/back direction of travel of the movable knife with their axes of rotation perpendicular to the plane of travel of the movable knife. The two cutter drive gears mesh together and rotate synchronously. Each cutter drive gear has a drive pin disposed at a position offset from the center of the end face. Oval holes with the long axis extending in the perpendicular direction are formed in the movable knife, and the drive pins of the cutter drive gears are inserted to these holes.
When the two cutter drive gears are turned by the drive power from the drive motor, the drive pins move in the forward/back direction of the movable knife while moving in the perpendicular direction inside the oval holes. The drive pins therefore contact the sides of the oval holes and move the movable knife in the forward/back direction. When the cutter drive gears turn one revolution, the movable knife travels between the forward position overlapping the fixed knife and then back to the retracted position forming a gap between the movable knife and the fixed knife. The cutter blade moving mechanism described in JP-A-2005-161481 has a coil spring that urges movable knife from the retracted position to the forward position.
In the cutter blade moving mechanism described in JP-A-2005-161481, the coil spring assists moving the cutter blade from the retracted position to the forward position. A low cost drive motor with relatively low output can therefore be used to drive the cutter blade. However, with a configuration that uses a coil spring to urge the cutter blade to the forward position, vibration, for example, can cause the movable knife to move toward the forward position. This creates a safety problem.